Aquatic Coleoptera Of Singapore: Species Richness, Ecology And Conservation # Author Hendrich, Lars Author Balke, Michael text Raffles Bulletin of Zoology 2004 52 1 97 145 journal article 10.5281/zenodo.13244881 2345-7600 13244881 Hydrovatus stridulus Biström, 1996 Hydrovatus stridulus Biström, 1996: 529 ; Balke et al., 1999: 325; Nilsson, 2001: 192 Material examined . – 68 specimens - Bukit Timah – 1 ex. , Bukit Timah , 13 Dec.1995 , coll. T. Wong & H.K. Lim ( ZRC ) ; 1 ex. , Bukit Timah Nature Reserve , coll. C.F. Lim ( ZRC ) . Central catchment area – 2 ex. , Nee Soon Swamp Forest , 7 Sep.1991 , coll. H. K. Lua ( ZRC ) ; 1 ex. , Nee Soon Swamp Forest , 19 Sep.1991 , coll. K. L. Yeo ( ZRC ) ; 1ex. , Nee Soon Swamp Forest , 26 Aug.1992 , coll. K. L. Yeo ( ZRC ) ; 7 ex. , Nee Soon Swamp Forest , 20 Sep.1993 , y 843, coll. C. M. Yang ( ZRC ) ; 6 ex. , Nee Soon Swamp Forest , 15 May.1992 , NS 4C, coll. C. M. Yang et al. ( ZRC ) ; 2 ex. , Nee Soon Swamp Forest , 17 Jun.1992 , NS 22, coll. K. L. Yeo et al. ( ZRC ) ; 1 ex. , Nee Soon Swamp Forest , 26 Aug.1993 , y 840, coll. K. L. Yeo ( ZRC ) ; 1 ex. , Lower Peirce Reservoire , 4 Jun.1992 , NS 18/19, coll. C. M. Yang et al. ( ZRC ) ; 3 ex. , Seletar Reservoire West , 25 Jan.1992 , y 780, coll. C. M. Yang & K. L. Yeo ( ZRC ) . Sungai Buloh - 5 ex. , Nature Reserve , 10 Jul.1992 , y 804, K.K.P. Lim coll. ( ZRC ) . Other areas - 1 ex. , “22 flew/ Singapore , C.J. Saunders B.M. 1929-369 / Hydrovatus stridulus mihi j. Balfour-Browne det.“ ( BMNH ) [ 4 ex. , with same data as holotype in BMNH and MZH ) ( Biström 1996 )] ; 37 ex. , Kent Ridge Park , Kent Ridge Pond , 6 Dec.1996 , coll. L. Hendrich & C. M. Yang ( CBH , ZRC ) . Distribution. – Thailand ,West Malaysia , Singapore ( Biström, 1996 ; Balke et al., 1999). Ecology. – Hydrovatus stridulus inhabits shallow, muddy water of open or semi-shaded primary swamps. The habitat is rich in rotten leaves. Dense submerged vegetation and sedges are usually present. The species also occurs in brackish waters of coastal swamps (Sungai Buloh Nature Park). Remarks. – Singapore is the type locality of this species.